KR100853441B1 - Clay modified with silane compound, polymer/clay nanocomposite containing the clay compound, and methods for preparing them - Google Patents

Abstract

A method for preparing a clay compound modified with a silane compound is provided to obtain a polymer/clay nanocomposite having excellent tensile modulus and tensile elongation while maintaining high transparency, and useful for elastic bodies for absorbing vibration and impact in various types of industrial machines. A method for preparing a clay compound modified with a silane compound comprises the steps of: (i) adding a silane compound to an aqueous solvent, and adding an acid thereto to perform hydrolysis; and (ii) adding clay to the hydrolyzed silane compound solution and agitating the mixture, followed by drying. In step (i), the aqueous solvent is a mixed solvent of ethanol/distilled water. The acid used in the step (i) is selected from the group consisting of phosphoric acid, acetic acid and formic acid.

Description

Clay compound with silane compound, polymer / clay nanocomposite containing the clay compound, and methods for preparing them

1 is a TGA analysis graph of clays modified with pure clays and silane compounds according to an embodiment of the present invention, and ((a): Comparative Example 1, (b): Example 1, (c): Implementation Example 2, (d): Example 3)

2 is a hydrophobic analysis graph of clays modified with pure clays and silane compounds according to an embodiment of the present invention, and (a): Comparative Example 1, (b): Example 1 and (c): Example 2, (d): Example 3)

3 is an XRD pattern analysis graph of clays modified with pure clays and silane compounds according to an embodiment of the present invention, (a): Comparative Example 1, (b): Example 1, (c): Implementation Example 2, (d): Example 3)

4 is an XRD pattern analysis graph of a polypropylene / clay nanocomposite according to an embodiment of the present invention, ((a): Comparative Example 2, (b): Example 4, (c): Example 5, (d): Example 6)

5 is a TEM image photograph of a polypropylene / clay nanocomposite according to an embodiment of the present invention, ((a): Comparative Example 2, (b): Example 6)

6a to 6d are SEM images and EDS mapping photographs of polypropylene / clay nanocomposites according to an embodiment of the present invention.

The present invention relates to a clay compound modified with a silane compound, a polymer / clay nanocomposite containing the same, and a preparation method thereof.

Composite materials are materials that have a superior performance than that of the matrix material while maintaining the original phase so that each material can be distinguished physically and chemically after complexing two or more kinds of materials. The component consists of a reinforced material or filler and a base material. The composite material was invented by the invention of unsaturated polyester compounded with glass fiber and phenolic resin and used as a gasoline tank of a fighter, and reinforcing fiber and functional polymer were developed. Since the oil crisis of the 1970s, energy saving has emerged as a buzzword in the industry, and research into composite materials with light weight and excellent specific strength and inelasticity has been actively conducted. Recently, nano-scale fillers have been released and dispersed in a polymer base material to attract attention of nanocomposites that have greatly improved strength and stiffness, barrier to gas or liquid, abrasion resistance, and heat resistance without damaging impact resistance, tensile strength, and transparency. In particular, the nanocomposite can significantly reduce the specific gravity of the composite because it can be expected to improve the physical properties in a smaller amount than conventional fillers, and it is economical as well as industrially because there is an advantage that can be manufactured by supplementing the existing equipment It has the advantage of excellent usability.

On the other hand, the polyolefin-based polymer of the polymer used as the base material is used as a very important polymer in terms of small specific gravity, excellent chemical stability and molding processability, economical. However, in the unfilled state, since the polymer has weak mechanical properties, a reinforcing filler is required to improve the strength. Furthermore, since the polyolefin-based polymer has nonpolar hydrophobicity, a high compatibility and good dispersibility filler is required. Required.

Generally, fillers of polyolefin-based polymers include calcium carbonate (CaCO ₃ ), talc, mica, glass fibers and the like [W. Qui, K. Mai and H. Zeng, J. Appl . Polym. Sci . , 1999, 71, 1537. However, in the case of using such a filler, the viscosity of the polymer / filler is increased and energy is consumed in the mixing process, and a lot of heat is generated to cause deterioration of the polymer. There is a limit.

Among the materials for overcoming these shortcomings, the clay has a structure in which several silicate layers are laminated, and the aspect ratio of the silicate layer is very large, ranging from 1000 to 2000. Because of its large specific surface area, it has a plate-like and stable network. In particular, montmorillonite is a very good material for polymer nanoparticle fillers because the silicate layers are easily swollen in water and the interlayers are opened [Pinnavaia, TJ Science 1983, 220 , 365]. Compared to silica or glass fiber, clay also has a reinforcing effect at the level of engineering plastics, and improves the recyclability of the composite, improves combustion resistance, reduces gas permeability, and disperses it to a size smaller than the wavelength of light. Even if added, it has the advantage of not lowering the transparency.

In order to enhance the reinforcing effect of the polymer by clay, it is necessary to completely disperse the silicate layer of the clay, or to insert a polymer and improve the compatibility of the silicate layer laminated structure and the polymer well mixed with each other so that the phase is not separated. The intercalation between the clay and the polymer is widened depending on the degree of compatibility, or the lamination structure of the clay is completely degraded and the silicate layer is peeled off.

To this end, studies have been conducted to add a compatibilizer to increase the hydrophobicity of the clay to improve compatibility between the clay and the polymer [M. Kawasumi, N. Hasegawa, M. Kato, A. Usuki and A. Okada, Macromolecules , 1997, 30 , 6333]. As a general compatibilizer, oligomers of which maleic-anhydride is hybridized are mainly used. However, this type of compatibilizer lowers the mechanical properties of the composite and makes it difficult to industrialize the nanocomposite because it is expensive.

Polymer / nanocomposite manufacturing technology is a technique that can improve the physical properties of the polymer by peeling the organic clay compound having a layered structure into a nano-sized layer by uniformly dispersing the plate-like organic clay compound having an aspect ratio of 100 or more in the polymer.

Generally, the polymer / nanocomposite is prepared by a solution method, a polymerization method, or a melt mixing method. The solution method is a method in which an organic clay compound is immersed in a polymer solution to insert a polymer into clay, and then the clay is dispersed in the polymer during drying. The polymerization method is a method of dispersing clay by inserting a polymer monomer into clay and then polymerizing the polymer between layers. Melting compounding is a method in which molten polymer chains are directly inserted between clay layers and mechanically mixed to disperse clay. This method complements the problem of deteriorating the physical properties of the composites, such as surfactants used in the solution method or polymerization method, and many nanocomposites manufactured using the same have been known since the 1990s.

Accordingly, the present inventors melt a clay compound having hydrophobicity and a polyolefin-based polymer having hydrophobicity while increasing the compatibility of the polymer with clay to increase the reinforcing effect of the polymer by clay. By producing a polymer / clay nanocomposite by mixing, it was confirmed that the mechanical properties of the composite is significantly improved by increasing the compatibility and dispersibility of the polymer and clay while using a small amount of clay to complete the present invention.

It is an object of the present invention to provide a clay compound modified with a silane compound substituted with 1 to 3 methoxy groups and a C ₁ to C ₂₀ alkyl group.

Another object of the present invention is to provide a method for preparing a clay compound modified with a silane compound.

Still another object of the present invention is to provide a polymer / clay nanocomposite containing a clay compound modified with the silane compound.

Another object of the present invention is to provide a method for preparing a polymer / clay nanocomposite containing a clay compound modified with the silane compound.

In order to achieve the above object, the present invention provides a clay compound modified with a silane compound substituted with 1 to 3 methoxy groups and a C ₁ to C ₂₀ alkyl group.

The present invention also provides a method for producing a clay compound modified with a silane compound.

Furthermore, the present invention provides a polymer / clay nanocomposite containing a clay compound modified with the silane compound.

The present invention also provides a polymer / clay nanocomposite containing a clay compound modified with the silane compound.

Hereinafter, the present invention will be described in detail.

The present invention provides a clay compound modified with a silane compound substituted with 1 to 3 methoxy groups and a C ₁ to C ₂₀ alkyl group.

In the clay compound according to the present invention, there is no particular limitation on the type of clay which can be used, preferably montmorillonite, bentonite, kaolinite, mica, hectorite, fluoride hectorite, saponite, bedelite, Organic or organic layering agents such as non-natural or synthetic layered clays such as nontronite, stevensite, vermiculite, halosite, volconscote, sukconite, margite, kenyalite pyrophyllite, or alkyl ammonium Clays such as montmorillonite can be used.

In addition, the silane compound according to the present invention consists of a silane group and an alkyl group, and is used to modify the clay. The alkyl group of the silane compound is preferably C ₁ ~ C ₂₀ It consists of alkyl and a silane group can be used substituted by 1 to 3 methoxy groups. More preferably, propyltrimethoxy silane (III) of Formula 1, octyltrimethoxy silane of Formula 2, and octadecyltrimethol of Formula 3 Oxy silane (octadecyltrimethoxy silane (ⅩⅧ)) and the like can be used. The silane compounds react with silanol (Si-OH) remaining on the surface of the clay to provide an alkyl chain to the clay. The alkyl chain serves to enhance the physical properties of the polymer / clay nanocomposites described below by increasing the compatibility with the polymer (compatibility), thereby enhancing the dispersion and interaction in the polymer of the modified clay.

In addition, the present invention comprises the steps of adding a silane compound to an aqueous solvent and hydrolyzing with a suitable acid (step 1); And

It provides a method for producing a clay compound introduced with a silane compound comprising the step (step 2) of adding and stirring clay to the solution of the silane compound hydrolyzed in step 1.

Step 1 according to the present invention is a step of adding a silane compound to an aqueous solvent and hydrolyzing with an acid.

As the silane compound, any silane compound capable of providing an alkyl group may be used, and preferably, a silane compound having a C ₁ to C ₂₀ alkyl group may be used. More preferably, propyl methoxy silane (III), octyltrimethoxy silane (oc), octadecyltrimethoxy silane (octadecyltrimethoxy) of Formulas 1 to 3 silane) and the like can be used. The silane compound may be used synthetically or commercially available. At this time, the amount of the silane compound added is preferably 10 to 20% by weight based on the clay. When the amount of the silane compound exceeds 20% by weight with respect to the clay, the physical properties of the composite material are lowered due to the unreacted silane compound, and the cost of the modified clay is increased. There is a problem that the adhesion to the composite material is lowered.

As the water-soluble solvent of step 1 according to the present invention, a water-soluble solvent capable of hydrolyzing the silane compound may be used. Preferably, a mixed solvent of ethanol / distilled water may be used. At this time, the mixing ratio of ethanol / distilled water is preferably 85 to 95% by weight: 5 to 15% by weight. In addition, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, formic acid, and the like may be used as the acid, and it is preferable to adjust the pH of the water-soluble solvent to 3-5 by adding them appropriately. At this time, when the pH of the water-soluble solvent exceeds 5, the silane compound has a problem of affinity with clay, and if less than 3, the silane compound has a problem that the reaction between the silane compounds occurs more than the clay surface. In addition, the aqueous solution in which the silane compound is added to the water-soluble solvent may be stirred and stirred for 1 to 3 hours. If the stirring time exceeds 3 hours, there is a problem that a large amount of the water-soluble solvent is evaporated, and if less than 1 hour, there is a problem that the unreacted silane compound remains in solution.

Next, step 2 is a step of adding clay to the silane compound solution hydrolyzed in step 1 and drying.

There is no particular limitation on the type of the clay according to the present invention, but montmorillonite, bentonite, kaolinite, mica, hectorite, fluoride hectorite, saponite, baydelite, nontronite, stevensite, Natural or synthetic layered clays such as vermiculite, halosite, volconscote, sukconite, margotite, kenyarite and pyrophyllite are used, and montmorillonite can be preferably used. In this case, the amount of clay added is preferably 0.5% by weight to 10% by weight. If the amount of the clay is more than 10% by weight, there is a problem in that the clay is agglomerated in the polymer matrix to lower the physical properties.

The stirring is preferably carried out at reflux for 20 to 30 hours at 60 ~ 80 ℃. If the stirring temperature exceeds 80 ℃ there is a problem that a large amount of water-soluble solvent is increased, if less than 60 ℃ there is a problem that the reactivity of the silane compound is lowered, the clay modification effect is lowered.

After the reaction, the reactant may be filtered, washed and dried to obtain clay modified with the silane compound. At this time, an aspirator may be used, ethanol may be preferably used as the washing solution, and a drying temperature is preferably 50 to 70 ° C. In addition, the drying is preferably carried out under vacuum.

The present invention also provides a polymer / clay nanocomposite containing a clay compound modified with the silane compound.

In the polymer / clay nanocomposite according to the present invention, the polymer is nonpolar and hydrophobic polymer of any kind, preferably polyethylene (PE), polystyrene (PS), polypropylene ( polypropylene (PP)), a polymer such as polybutadiene (polybutadiene) can be used, and more preferably polypropylene. The polymer may be synthesized or used commercially by methods widely used in the art.

In the polymer / clay nanocomposite according to the present invention, the content of the clay compound of the nanocomposite may be 1% by weight to 4% by weight. At this time, if the content of the clay compound is more than 4% by weight, the clay compound has a problem of aggregation in the polymer matrix, if less than 1% by weight there is a problem that the mechanical properties of the nanocomposite does not improve.

In another aspect, the present invention comprises the steps of mixing a clay compound and a polymer modified with a silane compound (step A); And

It provides a method of producing a polymer / clay nanocomposite comprising the step (A) of heating the product of step A) to a certain temperature to dry.

Step A) according to the present invention is a step of selecting and mixing an appropriate polymer with a clay compound modified with a silane compound.

The clay compound modified with the silane compound is mixed with the polymer by melt mixing using a twin screw extruder. The clay compound modified with the silane compound may be prepared by the steps 1 and 2.

The clay compound and the polymer is preferably mixed at a temperature range of 180 ~ 220 ℃. If the mixing temperature is higher than 220 ℃, the flow of the polymer is too high to reduce the shear force to destroy the laminated surface of the clay compound, if less than 180 ℃ the flow of the composite material is lowered, the problem of poor dispersibility of the clay compound There is.

The polymer may be any kind of polymer having nonpolarity and hydrophobicity. Preferably, a polymer such as polyethylene, polystyrene, polypropylene, polybutadiene, or the like may be used, and more preferably, polypropylene may be used. The polymer may be synthesized or used commercially by methods widely used in the art.

Next, step B) is a step of preparing a polymer / clay nanocomposite by heating and drying the resultant of step A) to a predetermined temperature.

At this time, the drying is preferably carried out in a vacuum for 10 to 50 hours, the drying temperature is preferably 50 to 70 ℃. If the drying time exceeds 50 hours, the composite is thermally deformed, thereby lowering the tensile strength. If the drying time is less than 10 hours, there is a problem that moisture remains in the composite. In addition, when the drying temperature exceeds 70 ℃, deterioration association of the composite is generated, if less than 50 ℃ there is a problem of low moisture removal efficiency.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are merely to illustrate the invention, the present invention is not limited by the following examples.

Example 1 Preparation of Clay Compound Modified with Propyltrimethoxysilane (III)

2 g of commercially available propyltrimethoxysilane (III) was added to 400 g of a mixed solvent of ethanol (90 wt%) / distilled water (10 wt%) adjusted to pH 4.0 with acetic acid and stirred for 2 hours, To the mixture was added 20 g of montryllonite (Cloisite ^® 20A, Southern Clay Co. USA) and stirred at reflux for 24 hours at 70 ° C. After the reaction, an aspirator was used to wash several times with alcohol. The washed product was vacuum dried at 60 ° C. for 48 hours to prepare a clay compound modified with propyltrimethoxysilane (III).

Example 2 Preparation of Clay Compound Modified with Octyltrimethoxysilane

A clay compound modified with octyltrimethoxysilane was prepared in the same manner as in Example 1 except that octyltrimethoxysilane (신) was used instead of propyltrimethoxysilane (III).

Example 3 Preparation of Clay Compound Modified with Octadecyltrimethoxysilane

A clay compound modified with octadecyltrimethoxysilane was prepared by the same method as Example 1 except for using octadecyltrimethoxysilane instead of propyltrimethoxysilane (III). It was.

Comparative Example 1

Commercially available montryllonite (Cloisite ^® 20A, Southern Clay Co. USA) was used.

analysis

(1) Water absorption rate analysis

The clay compound modified with the silane compound of Examples 1 to 3 was vacuum dried at 80 ° C. for 12 hours to form a saturated steam machine at 30 ° C. and 200 mbar in a vacuum oven (VO-10X, Lab Camp). After leaving for 24 hours, the weight was calculated by measuring the thermogravimetric analyzer (TGA, Q50, TA), through which the water absorption is analyzed and shown in FIGS. 1 and 2.

(2) X-ray diffraction  analysis( WAXD )

The interlayer distance of the clays contained in the nanocomposites was measured by Rigaku's wide angle X-ray scattering (WAXD). The wavelength of CuKα was applied to 40 kV and 40 mA, and the diffraction angle 2θ was scanned at a range of 2 ° to 10 ° at a speed of 1 ° / min, and the results are shown in FIG. 3. The interlayer distance of clay was represented by Bragg's equation below. It is calculated by using the same as shown in Table 1.

nλ = 2d ₀₀₁ sinθ

(n: integer, λ: X-ray wavelength, d ₀₀₁ : interlayer distance, θ: diffraction angle)

Psalter 2θ (°) d ₀₀₁ (nm) Example 1 3.7 2.4 Example 2 3.6 2.5 Example 3 3.3 2.7 Comparative Example 1 3.7 2.4

1 is a TGA analysis graph of Comparative Example 1, Example 1, Example 2 and Example 3. 2 is a graph analyzing the correlation between moisture absorption rates of Comparative Example 1, Example 1, Example 2 and Example 3. FIG. As shown in FIG. 1, it was found that for Example 2 (2% by weight) and Example 3 (2% by weight), the mass reduction of Comparative Example 1 (2% by weight) was smaller.

As shown in FIG. 2, the water absorption was significantly decreased in the order of Comparative Example 1 (0.9% by weight)> Example 1 (0.79% by weight)> Example 2 (0.55% by weight), and was reduced to that of Example 3 (0.52% by weight). Moisture absorption was slightly less than Example 2 (0.55 wt.%).

As the carbon number of the silane compound increases, the water absorption of the clay compound modified with the silane compound is lower than that of the clay before the modification, indicating that the hydrophobicity is increased.

3 is a graph showing a WAXD pattern of Comparative Example 1, Example 1, Example 2, and Example 3. FIG. As shown in FIG. 3, it can be seen that 2θ of Comparative Example 1 is 3.7 °, 2θ of Example 1 is 3.7 °, 2θ of Example 2 is 3.6 °, and 2θ of Example 3 is 3.3 °, similar to before modification. have.

In addition, Table 1 has shown the interlayer distance of Comparative Example 1 and Examples 1-3. Comparative Example 1 is 2.4 nm, Example 1 is 2.4 nm, Example 2 is 2.5 nm, Example 3 is 2.7 nm it can be seen that the interlayer distance increases slightly as the alkyl chain length of the silane compound increases. However, the reason for the slight increase is that the reforming reaction occurs mainly at the edge of the clay.

Example 4 Preparation of Nanocomposites of Clay Compounds Modified with Polypropylene / Propyltrimethoxysilane (III)

As polypropylene, homo-polypropylene (YUHWA POLYPRO ^® 4017) having a weight average molecular weight of about 250,000 g / mol was used.

294 g of the polypropylene was physically primary mixed with 6 g of the clay compound of Example 1 and then melt mixed by heating to 200 ° C. in a twin screw extruder (L / D = 40). The product was dried under vacuum at 60 ° C. for 24 hours to prepare a polymer / clay nanocomposite containing a clay compound modified with propyltrimethoxysilane (III).

Example 5 Preparation of Nanocomposites of Clay Compounds Modified with Polypropylene / Octyltrimethoxysilane

A polymer / clay nanocomposite containing a clay compound modified with octyltrimethoxysilane was prepared in the same manner as in Example 4 except that Example 2 was used instead of Example 1.

Example 6 Preparation of Nanocomposite of Clay Compound Modified with Polypropylene / octadecyltrimethoxysilane

A polymer / clay nanocomposite containing a clay compound modified with octadecyltrimethoxysilane was prepared in the same manner as in Example 4 except that Example 3 was used instead of Example 2.

Comparative Example 2 Preparation of Polypropylene / Clay Composite

The polymer / clay nanocomposite containing the unmodified clay was prepared in the same manner as in Example 4 except that the unmodified montmorillonite was used instead of the modified clay compound.

Comparative Example 3 Preparation of Polypropylene Polymer

Polypropylene was prepared by heating to 200 ° C. in a twin screw extruder to melt.

analysis

The polypropylene / clay nanocomposites produced by the method were measured in WAXD and the graph is shown in FIG. 4, and the interlayer clay distances were calculated in Bragg's equation and are shown in Table 2.

Psalter 2θ (°) Interlayer Distance (nm) Example 4 2.9 3.0 Example 5 2.9 3.0 Example 6 2.9 3.0 Comparative Example 2 2.7 3.3

In addition, the morphology (Morphology) of the composite prepared by cutting to 90 nm thickness using a diamond blade with an ultramicrotormer (RMC / MTX) using a transmisson electron microscopy (TEM) (philips CM200) Irradiation at 120 kV is shown in FIG. 5.

On the other hand, after breaking the complex of Comparative Example 2, Examples 4 to 6 under liquid nitrogen, the dispersibility of the fracture surface and the modified clay compound of the scanning electron microscope / energy dispersion analyzer (SEM / EDS, Hitachi, S-4200) Irradiation with the results are shown in Figures 6a to 6d.

4 is a graph comparing the patterns of WAXD of Comparative Example 2, Example 4, Example 5 and Example 6. FIG. Based on this, the interlayer distance of clay of each nanocomposite was calculated and shown in Table 2. As shown in Table 2, Comparative Example 2 is 3.3 nm, Example 4 is 3.0 nm, Example 5 is 3.0 nm, and Example 6 is 3.0 nm. After mixing with polypropylene, the interlayer distance of the nanocomposite containing modified clay was found to decrease slightly compared to the interlayer distance of the nanocomposite containing pure clay. It can be interpreted that the distance between layers is constant irrespective of each modified polypropylene / clay composite type, but it can be seen that the distance between layers increased when compared with the modified clay compound itself without mixing the polymer.

5 shows the morphology of Comparative Example 1 and Example 6 via TEM. As shown in FIG. 5, the interlayer distances of Comparative Example 1 and Example 6 seem almost the same. This shows a similar tendency to the results of FIGS. 4 and 2, in which the layers of clay have a structure that is orderly stacked in a polypropylene matrix.

6A to 6D show photographs of the SEM (left) and Si distribution mapping images (right) through EDS for the fracture surfaces of Comparative Examples 2, 4, 5, and 6; In each EDS Si distribution mapping picture, bright spots indicate the position of Si atoms. As shown in FIGS. 6A to 6D, it can be seen that the number of points decreases in the order of Comparative Example 2, Example 4, Example 5, and Example 6, and in particular, in the mapping picture of Example 6, bright spots are almost found. Can't see This indicates that the more bright spots occur in the clay when the composite breaks, the more Si atoms are located on the fracture surface. It can be seen that the agglomeration degree of the clay is reduced according to the alkyl chain length of the modified clay compound, and the clay of Example 6 can be seen to be well dispersed with little agglomeration. Therefore, it can be seen that when the clay is modified with a silane compound having a long alkyl chain, the compatibility between the clay and the polypropylene is increased.

Psalter Number of points (pcs / cm ² ) Example 4 1.7 × 10 ⁵ Example 5 8.0 × 10 ⁴ Example 6 1.5 × 10 ⁴ Comparative Example 2 5.7 × 10 ⁵

Experimental Example 1 Measurement of Mechanical Properties

In order to determine the improvement of mechanical properties of the clay nanocomposite modified with the polymer / silane compound according to the present invention, the following experiment was performed.

(1) Tensile Properties Measurement

Tensile properties of the nanocomposite were used for the Univesal Testing Machine (UTM, LLOYD Instruments, Model No. LR10K). The clay nanocomposite modified with the polypropylene / silane compound prepared in Examples 4 to 6, the polypropylene / pure clay nanocomposite prepared in Comparative Example 2, and the polypropylene specimen prepared in Comparative Example 3 were used as dumbbell type 3 (KSM). 6518) in the form It was measured at a test rate of 5mm / min by ASTM D-638, the load cell was used 500N. Each measured value was measured at least five times to obtain an average value.

Table 3 shows the measurement results of the tensile properties according to the specimens.

Psalter Tensile Modulus (MPa) Tensile Elongation (%) Yield Stress (MPa) Example 4 1830 10 36 Example 5 2010 10 37 Example 6 2340 85 36 Comparative Example 2 1610 10 35 Comparative Example 3 1480 148 36

As shown in Table 1, the yield stress is similar to all 35 ~ 37 MPa, but compared to Comparative Example 3 (tensile modulus: 1480 MPa) that is pure polypropylene, Comparative Example 2 (tensile modulus: 1610 MPa), Example 4 (Tensile modulus: 1830 MPa), it was found that the tensile modulus of Example 5 (tensile modulus: 2010 MPa) and Example 6 (tensile modulus: 2340 MPa) were improved, and in particular, the tensile modulus of Example 6 was comparative. It was found that 60% increase compared to 3. On the other hand, the tensile elongation of Comparative Example 3 is 148%, the tensile elongation of the composite of Comparative Example 2, Examples 4 to 5 was reduced to 10%, it was confirmed that the tensile elongation of Example 6 appears to be relatively high to 85%. . Therefore, although all clays act as reinforcing fillers, there are differences in degree, but it can be seen that the tensile modulus is improved regardless of the type of clay. Particularly, Example 6 significantly improves the tensile modulus than the other examples. It can be seen that the reduction in tensile elongation is prevented. From this, it can be seen that the interfacial interaction between the clay compound modified with the C ₁₈ alkyl chain and the propylene compound and the polypropylene was improved.

As described above, the polymer / clay nanocomposite according to the present invention has excellent mechanical properties such as tensile modulus and tensile elongation while maintaining transparency, such as automotive, electronic information, construction civil engineering, and medical use requiring such characteristics. It can be usefully used in parts and the like in which the physical properties and transparency of the elastic body have a great influence on the durability and quality of the finished product, such as the vibration and shock absorbing elastic body of the machine.

Claims (21)

delete delete delete delete delete Adding a silane compound to a water-soluble solvent and adding an acid to hydrolyze (step 1); And The method of producing a clay compound modified with the silane compound comprising the step of adding a clay to the silane compound solution hydrolyzed in step 1 and stirring, followed by drying (step 2). The method of claim 6, wherein the water-soluble solvent of step 1 is a method of producing a clay compound modified with a silane compound, characterized in that a mixed solvent of ethanol / distilled water. The method of claim 7, wherein the mixing ratio of ethanol / distilled water is 85 to 95% by weight: 5 to 15% by weight of the method for producing a clay compound modified with a silane compound.  The method of claim 6, wherein the acid of step 1 is any one selected from the group consisting of phosphoric acid, acetic acid and formic acid. 7. The method of claim 6, wherein the pH of the silane compound solution of step 1 is adjusted to 3 to 5. The clay according to claim 6, wherein the clay is montmorillonite, bentonite, kaolinite, mica, hectorite, fluoride hectorite, saponite, bedelite, nontronite, stevensite, vermiculite, halosite, volconscote Silane compound, characterized in that any one selected from natural or synthetic layered clay selected from the group consisting of sukconite, margotite, kenyarite and pyrophyllite, or their organicized clay Process for preparing clay compounds modified with 12. The method of claim 11, wherein the clay is montmorillonite or organic clay thereof. delete delete delete delete delete delete delete delete delete

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